Nova Express impossible!

:xI have a level 48 balance wizard and am currently trying to complete the quest 'Nova Express' to get the spell 'power nova'.I have to collect some raw crystal in the necropolis, in a tower (not sure what it's called). The problem is that i'm not strong enough and struggle to complete the first fight as i'm used to fighting in groups with at least one other person. It is a solo quest and i was wondering if anyone has any tips for me.

Your mander minion will be a great deal of help to you in this challenge. If you have any spare Crowns, considering hiring a Henchman to assist. You can hire a Henchman when you're in a duel by selecting the SHOP button and clicking the Henchman tab. Select the Henchman to hire and they will appear and cast in that same turn.

If you want the prize, you have to build the ladder rung by rung. There are no shortcuts.

The Plague Oni has an 80% resistance to Balance magic, which means such attacks are more or less useless against it. The Oni takes 50% extra damage from spirit (Myth, Death, and Life) magic. Since the biggest damage-per-pip is done by

One thing you might consider is going to the Bazaar and buying a few Ninja Pig (Myth) treasure cards (about 450 each). These use 5 pips and do 640 base damage. You can set them up with Balanceblade, Spirit Blade, and Spirit Trap and do over 2000 damage if you don't have Weakness cast on you and the Oni doesn't have a Spirit Shield on itself.

Take out the minion first with Judgement, then buff yourself for the Oni.